Expressions are not tacit nor functional. Function definitions are. +/ *: 4 5 6 NB. this is an expression, not a function 77 f =. [: +/ *: NB. this is a function definition, tacit f 4 5 6 NB. this expression involves the above function 77
OK? Regards, Bo --- Den lør 8/8/09 skrev bill lam <[email protected]>: > Fra: bill lam <[email protected]> > Emne: Re: [Jprogramming] tacit definition (was: Using # item by item ...) > Til: [email protected] > Dato: lørdag 8. august 2009 19.43 > On Sat, 08 Aug 2009, Sherlock Ric > wrote: > > > From: Raul Miller > > > > > > If it matters, the "official" definition of > tacit:seems to be: > > > > > > http://www.jsoftware.com/help/dictionary/intro.htm > > > > > > "...functional or tacit > programming that requires no explicit > > > mention of the arguments > of a function (program) being > > > defined, and the use of > assignment to assign names to > > > functions..." > > > > > > The dictionary also mentions that 13 : may be > used to create > > > tacit verbs. > > > > > > (Essays can provide very good and useful material > but usually > > > the dictionary will trump them.) > > > > > > [That said, bill lam has already answered and > explained what > > > he really means, and my post, here, was inspired > by some > > > points raised in past threads.] > > > > After reading Bill's post I found myself grappling in > my own mind with what was a tacit expression and what > wasn't, which was why I started/renamed this thread. I think > Dan's post does a pretty good job of describing sorts of > ideas I was/am trying to reconcile. The dictionary > description (I'm not sure if it is really a definition?) > didn't really clear things up for me. > > > > If I write a "top level sentence" in the session > manager > > +/ 4 5 6 > > Is it tacit or explicit? Is my sentence a) defining a > function, b) executing a function, or c) both? > > I'm thinking c), and given that the arguments are > given but not explicitly referred to, I'd also suggest that > this is a tacit expression? > > > > What about: > > +/ *: 4 5 6 > > How is this described? Is a function being defined? > (maybe, but I'm not sure!) If so, there doesn't seem to be > any explicit reference to the arguments - so is it therefore > tacit? > > > > I'll take Raul's quotation to be official. It refers to a > style of > programming by defining a series of names with other names > without > explicit arguments in its reasoning. > > take the example of standard deviation (not sure correct or > not). > > sum=: +/ > mean=: sum % # > deviation=: sum - mean > meansquare=: *:@deviation % # > stddev=: %:@meansquare > > certainly it is not about mechanically replacing x or y > with [ and ] > because x or y never appeared in the first place. > > -- > regards, > ==================================================== > GPG key 1024D/4434BAB3 2008-08-24 > gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > Find din nye laptop på kelkoo.dk. Se de gode tilbud her - http://dk.yahoo.com/r/pat/mm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
